Characterization of 86 Bruxing Patients andLong-Term Study of Their Management WithOcclusal Devices and Other Forms of Therapy

of ¡53 patients screened, 86 answered positively to questionsdesigned to identify bruxers. The bruxing patient profile revealedthat 100% had working excursive interferences, 78% had balanc-ing excursive interferences, and 95.4% had a premature contactinto maximum intercuspation. Most of the bruxing patients had achief complaint that related to pain, and 89.6% of the patients hada craniomandibular disorder. The patients were initially managedwith an anterior deprogramtner and were later managed with otherocclusal devices as signs and symptoms dictated. Definitive treat-ment was determined by the patient's maxillomandibular relat-ionship.J OROFACIAL PAIN 1993;7:54-60

Daniel Yustin, DDS, MSFormer Prosthodontics ResidentDepartment of Fixed Prosthodontics

and OcclusionUniversity of Texas at HoustonHealth Sciences CenterDental BranchHouston, Texas

Peter Neff, DDS, MSProfessor and ChairmanDepartment of OcclusionOeorgetown UniversitySchool of DentistryWashington, DC

M.R. Rieger, MS, PhDAssociate ProfessorDepartment of Oral Biomaterials

Thomas Hurst, DDS, MSProgram DirectorGraduate Prosthodontics

University of Texas at HoustonHealth Sciences CenterDental BranchHouston, Texas

Correspondence to:Dr Daniel Yustin2425 Bloor Street WSuite 302Toronto, Ontario M6S 4W4Canada

The term bruxistn is defitied as "the parafunctional grinditigof teeth.'" If left untreated, bruxistn can lead to attrition oftooth surfaces, loss of vertical dimension of occlusion,

increased muscle tonus, and adaptive changes in the tetnporo-mandibular joints (TMJs).' The damage to masticatory structures isrelated to the duration and magnitude of force applied during theparafunctional activity."

Controversy exists concerning the etiology of bruxism and themethods of management. Some practitioners believe mild cases ofbruxism are of no concern because resulting tooth wear and TMJremodeling is "adaptive and may be viewed as an accepted aspectof aging.'" The etiology of bruxism is also not well understood.Historically, it was believed that bruxism was a result of occlusalprematurities and interferences.-"""" Treatment was then directed ateliminating interferences by establishing ideal occlusion.' Onerecent study'' suggests that occlusal interferences may increasebruxism, but other studies^"" suggest that the occlusal conditionhas little effect, if any, on bruxism and that the habit appears to berelated to the patient's emotional status.

Despite an apparent lack of agreement within the dental profes-sion, the most common method of managing the bruxing patient isthrough the use of occlusal devices. Much controversy exists in thisarea concerning design preference and mode of therapeutic actionof the devices.''-'" Recent studies comparing different occlusaldevices have had unexpected results, as factors that were thoughtto be therapeutic (such as canine guidance) were found not toaffect bruxism." '- However, a significant number of the studies hadexperimental design flaws (such as possible improper occlusaldevices for the type of therapeutic action required, insufficient timefratnes, and inadequate patient sample size).

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Table 1 Chief Complaints of 86 Bruxing Patients Results

Head- or neck-related pain 45Bruxism 15TMJ click 10Bad bite 8Can't open mouth wide 3Loss of tooth structure Cor verticai dimension of occlusion) 2

Need extensive restorative dentistry 1Nonsymmetric face 1

Second opinion for orthognathic surgery 1

This study subjectively and objectively evaluatedthe use of occlusal devices in the management ofpatients who were aware that they ground theirteeth, although bruxism may not have been theirprimary reason for seeking treatment. The bruxingpatients may have had other signs and symptomsof craniomandibular dysfunction (CMD) treatedsimultaneously in the course of treatment. Thepatients' clinical signs and symptoms determinedthe success of treatment. Therefore, in this study,the patients had to be aware of their parafunction-al habit; if not, they were excluded from this studybecause they would not be able to provide appro-priate feedback.

Materials and Methods

The subjects of this study were patients treated atthe Georgetown University School of Dentistry,Department of Occlusion, for an occlusal problem,CMD, or occlusal parafunctional activity. Recordsof their course and modes of treatment were kepton computer files by the treating resident, underthe supervision of the department chairman. Aseries of screening questions was used to identifybruxing patients. Each patient's chief complaint,signs and symptoms, preliminary diagnosis, initialmanagement, any subsequent management, anddefinitive treatment were documented and com-piled into tabular form. An intraoral occlusalanalysis using mylar articulating ribbon was per-formed to determine whether the patient had (1) apremature contact into maximum intercuspation,(2) a lateral working interference, or (3) a lateralbalancing interference. The patient's maximumopening was measured. The TMJ was palpated todetermine whether the joint was painful andwhether a click was present when the patientopened and closed. The patient was also ques-tioned to determine the presence and number ofheadaches or neck aches experienced per month.

A total of 353 patients presented for treatmentduring the time of this study; 86 (24.4%) wereidentified as bruxers. There were 68 women and18 men (comprising 79% and 21% of the sample,respectively), and the average age was 36.4 years.Intraoral occlusal analysis revealed 82 patients(95.4%) had a repeatable premature contact tomaximum intercuspation. All 86 (100%) had pos-terior working interferences in lateral excursivemovements, and 67 (78%) bad posterior non-working interferences in lateral excursive move-ments. A patient was considered to have an inter-ference in excursive movements if contact on pos-terior teeth precluded canine guidance in lateralexcursive movements. Evaluation of tbe TMJsrevealed 56 patients (65%) had a unilateral orbilateral click, with 51 (59.3%) having TMJ pain.Multiple headaches or neck aches were found tooccur monthly in 52 (60.4%) of the patients.

Only 15 patients had a chief complaint of brux-ism. Most (45) had chief complaints that related topain - headaches or neck aches, tooth pain, orTMJ pain (Table 1). Discussions with patientsconfirmed that bruxism was not their primaryconcern; pain was the major reason bruxingpatients sought treatment. Patient education was afactor in the treatment of bruxism, since patientsinformed about bruxism causing loss of toothstructure, occlusal changes, increased muscletonus, and CMD were more likely to have brux-ism managed by the dentist.

Diagnosis

Only 4 of the patients (4.6%) were diagnosed asbruxers with no associated TMJ or muscle symp-toms. Thirty-five patients (40.7%) had musclespasms associated with bruxism, with 38 (44.2%)baving an internal derangement of the TMJ withor without muscle spasm. Four of the patientswere diagnosed as having degenerative joint dis-ease (osteoarthritis; 4.6%). Therefore, a total of77 (89.6%) had CMD.

Initial Treatment

Initial treatment (normally at the first visit) for thebruxing patient consisted of an anterior dépro-grammer constructed of autopolymerizing acrylicresin on the patient's maxillary central incisors,which were lubricated with petroleum jelly (Eig 1).Maxillary and mandibular alginate impressionswere also made at the first visit. When polymer-

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Fig 1 Intraoral view of the anterior déprogrammershowmg separation of the posterior teeth.

Fig 2 View of the occlusal surface of the anteriordéprogrammer showing desired occlusal contacts in cen-tric occlusion and eccentric movements. Only the mesialaspect of the mandibular central incisors is in occlusion.

Fig 3 Intraoral view of anterior déprogrammer on a 2-mm Biocryl vacuum-formed framework used for extend-ed time management.

ized, the acrylic resin was adjusted until themandibular central incisors contacted a flat planewith a separation of 1.0 to 1.5 mm in the area ofthe first molar""'' (Fig 2). The bruxing patientswere specifically managed with an anterior dépro-grammer because this type of applicance (1)reduces the amount of tooth contact, (2) allowsfor the reduction of muscular function," and (3)alters the input to the central nervous system byproprioception. The patients were instructed to

wear the anterior déprogrammer that night whilesleeping. The next day, diagnostic casts were artic-ulated using a centric relation record obtainedwith the aid of the anterior déprogrammer."""

The patient's symptoms were noted, and thepatient was scheduled for a réévaluation. After 2weeks, patients were given either a new anteriordéprogrammer, a mandibular centric relationdevice, or an anterior reprogrammer or reposition-ing device, depending on their response to treat-ment. If the patient was comfortable and therewere no clinical signs of dysfunction, a second,more stable anterior déprogrammer was con-structed (Fig 3). The new anterior déprogrammerwas constructed on a 2-mm Biocryl (BuffaloDental, Brooklyn, NY) vacuum-formed frame-work and was used for a minimum of 2 months.Aside from the Biocryl framework, this devicefunctioned in exactly the same way as the anteriordéprogrammer constructed of autopolymerizingacrylic resin. At the end of treatment, the patient'scondition was evaluated for stability and definitivetreatment.

If the patient's response to the first anteriordéprogrammer suggested there was muscle dys-function and signs and symptoms of muscle hyper-activity were not relieved, a mandibular centricrelation oeelusal device was constructed (Figs 4and 5)."'" The mandibular centric relation devicecan be worn easily during the day and will providemore surface area for functional stability. Thepatient was instructed to use the anterior depro-

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Fig 4 Intraoral view of mandibular centric relationocclusal device used when 24-hour support of temporo-mandibular articulation is indicated

Fig 5 Occlusal view of mandibular centric relationocclusal device showing desired centric occlusion con-tacts with immediate posterior disocclusion in excursivemovements. (Contacts are highlighted for clarity.)

grammer for sleeping; this, in combination withthe mandibular centric relation occlusal device,provided 24-hour support for the stomatognathicsystem. The design of the mandibular centric rela-tion device allowed the maxillary posterior lingualcusps to contact evenly a flat occlusal plane, withthe anterior teeth in lighter contact." This waschecked by pulling Mylar articulating ribbon outof the anterior teeth when the patient closed. Thedesign still allowed canine guidance in lateralmovements and incisai guidance in protrusivemovements, with complete posterior disocclusionin excursive movements.

Finally, if the patient, after 2 weeks' manage-ment with the anterior déprogrammer, exhibitedsigns of TMJ dysfunction such as a click, pain, ordeviation of the mandible upon opening or clos-ing, an anterior reprogrammer or repositioningdevice was used to manage the occlusion at a max-illomandibular relationship at which the jointwould not exhibit signs of dysfunction.--̂ "--- Thepatient continued to use the reprogrammer untilsigns and symptoms were eliminated for a suitablelength of time (normally 6 to 8 weeks) to decreaseinflammation and to allow step-back proceduresto be initiated."--'

Of the 86 patients who began therapy with ananterior déprogrammer, 41 had further manage-ment with a mandibular centric relation occlusaldevice and 12 patients were placed on an anteriorrepositioning occlusal device. There may have

been an overlap of management modality as signsand symptoms dictated.

Definitive Management

The average length of therapy using an occlusaldevice was 15.5 months. After the patient reportedthat symptoms were alleviated and after it wasjudged that the condition had stabilized, thepatient was evaluated for readiness for definitivetherapy. Two criteria were used in making thisdetermination: a normal and anatomically com-patible TMJ and relaxed musculature with no dis-comfort upon palpation.-' There were five optionsfor definitive management with which temporo-mandibular articulation could be maintained.These were as follows.

1. For some patients, it was possible to continuefunctioning with occlusal devices, returningperiodically for follow-up adjustments andevaluations. Patients had various reasons forelecting to continue management with theocclusal devices: comfort, finances, an inabili-ty to cope with further dental treatment. For21 patients (43%), this option provided aviable method of continually supporting thetemporomandibular articulation while reduc-ing, if not eliminating, the bruxism.

2. If the patient's occlusion was within the ruleof thirds as described by Burch'' and pre-sented by Neff,-'' occlusal adjustment could

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provide support of the temporomandibulararticulation. Three patients (8%) were man-aged in this manner.

3. A third possibility, especially for patientswhose teeth had previous restorations or hadbeen subjected to years of trauma or attrition,was prosthodontics, whether selective crownsor fixed or removable partial dentures.Fourteen patients (30%) were managedprosthodontically.

4. If the patient had few restorations and thedentition was sound (albeit malposed), ortho-dontic therapy was considered. Seven patients(16%) were managed in this way, with thedentist working closely with the orthodontist.

5. In some patients orthognathic surgery wasused in combination with orthodontic treat-ment to correct severely malposed maxillaryand mandibullar arches. This was the treat-ment of choice for cases involving anteriorrepositioning. Four patients (8%) requiredthis form of management.

Discussion

This study developed a profile of the typicalpatient who presented to the GeorgetownUniversity School of Dentistry, Department ofOcclusion, and followed the management of thesepatients with regard to their bruxism. Perhaps themost obvious and perplexing aspect of the patientprofile was that all the patients managed had later-al excursive interferences (100% had workinginterferences and 78% had nonworking). This wasconsidered perplexing because much of the recentpublished data indicates a lack of relation betweenocclusion and bruxism.''"" The recent trend amongmany practitioners in this field is to consider brux-ism a centrally mediated sleep disorder precipi-tated by stress.'

Although it was not our intention to determinethe etiology of bruxism, the results indicated thatthe typical patient had gross occlusal discrepancies,especially in excursive movements. While many ofthese occlusal discrepancies may have been causedby tooth attrition due to bruxism, the fact that allthe patients had working interferences may indicatethat a relationship exists between the bruxism andocclusion. This is supported by a recent studywhich suggested that placement of a 0.1-mmocclusal interference in the area of the first molarcould induce bruxism.' It has been shown in EMGstudies that bruxism is predominantly associatedwith stage 2 and REM stages of sleep.' It has also

been shown that both bruxers and nonbruxershave an increase in EMG activity; however, insteadof grinding their teeth, nonbruxers tend to have anincrease of body movement.' More research isneeded in this area to determine whether occlusalinterferences in excursive movements distinguishthe bruxers from the nonbruxers.

The patient profile also showed a high correla-tion between bruxism and dysfunction of the tem-poromandibular articulation. These data supportother data'^-'' concerning the relationship betwenbruxism and temporomandibular articulation dys-function.'' The pain experienced can be caused ifthe condyle is distally positioned by microtraumaand violates the space occupied by the highly vas-cular and innervated retrodiscal tissue.-'

Our patients were managed with the use of ananterior déprogrammer. The anterior déprogram-mer was used to (1) separate the posterior teeth,(2) relax the masticatory muscles,'*''-' (3) deter-mine whether the TMJs were normal,-^ (4) reducetooth contact, (5) alter proprioception to the cen-tral nervous system, and (6) register the particularposition of the TMJs.''

Many patients found relief from bruxism withthe use of an anterior déprogrammer which freedthe mandible from any tooth-guided positition andprevented further tooth attrition. Also, previousstudies^ •-' have shown that an anterior déprogram-mer would function to protect the patient from thedeleterious effects of bruxism to the tooth struc-tures, the masticatory muscle, and the TMJs. Someof the patients needed further support of the tem-poromandibular articulation because the anteriordéprogrammer did not relieve all signs and symp-toms of dysfunction. Because the anterior dépro-grammer could not be worn at all times, amandibular centric relation occlusal device or amandibular reprogrammer was provided for thesepatients to allow for maximum support of thetemporomandibular articulation during the day.The anterior déprogrammer functioned for sup-port at night. The average length of therapy usingan occlusal device was 15.5 months, with theshortest time being 2 months. This may be onereason that experimental data may not correlatewell with clinical data; many experimental dataare collected over time periods of less than 2months.''''•'"'•^"''•"

Summary

Out of 353 patients presented for screening, 86were diagnosed as bruxers. Patient profile analysis

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revealed that 79% were female, 21% were male,mean age was 36.4 years, 65.1% had TMJ click,and 59.3% had TMJ pain. All patients had poste-rior working interferences and 78% had balancinginterferences, with 95.4% having a premature con-tact into maximum intercuspation. Diagnosis ofthe patients revealed that 40.7% suffered frommuscle spasms, 44.4% had an internal derange-ment of the TMJ with or without muscle spasm,4.6% had osteoarthritis, 4.6% had a loss of verti-cal dimension of occlusion, 4.6% had bruxismwith no other signs or symptoms, and 1.2% hadocclusal trauma. The management of the patientsconsisted of construction of an anterior dépro-grammer, with additional occlusal devices as thepatient's signs and symptoms dictated. The aver-age length of management with occlusal deviceswas 15.5 months. Definitive forms of treatmentwhen the patient's condition was considered stablewere occlusal devices (43%), prosthodontics(30%), orthodontics (16%), occlusal adjustment(8%), orthognathic surgery (8%), and referral toneurologist (2%).

The bruxing patients in this study had occlusaldiscrepancies in excursive movements especially.These interferences are factors that may distin-guish bruxers from nonbruxers.

References

1. Glossary of prosthodonric terms. J Prosthet Denr1987;58:723.

2. Dawson PE. Evaluation, Diagnosis, and Treatment ofOcclusal Problems. Baltimore: Mosby, 1989:49-50.

3. Krough-Poulson WG, Olson WG. Occlusal disharmoniesand dysfunction of the stomatognathic system. Dent ClinNorth Am 1966; 726-735.

4. Mohl ND, Zarb G, Carlsson G, Rugh J. A Textbook ofOcclusion. Chicago: Quintessence, 1988:249.

5. Carlsson GE, Droukas B: Dental occlusion and health ofthe masticatory system. J Craniomand Pract1984;2:141-147.

6. Ramjford SP. Bruxism, A clinical and electromyographicstudy. J Am Dent Assoc 1961;62:21.

7. Randon K, Carlsson K, Edlund J, Obert T. The effect of anocclusal interference on the masticatory system. OdontRev 1976;27:245-255.

8. Takeda Y, Ishihara H, Kobayashi Y. The influences ofocclusal interferences on nocturnal sleep and massetermuscle activity. J Dent Res 1989;68:936.

9. Attanasio R. Nocturnal bruxism and its clinical manage-ment. Dent Clin North Am 1991;35:245-252.

10. Clark GT, Beemsterboer PL, Rugh JD. Nocturnal massetermuscle activity and the symptoms of masticatory dysfunc-tion. J Oral Rehabil 1981;8:279-286.

11. Rugh J, Barghi N, Drago C. Experimental occlusal dis-crepancies and nocturnal bruxism. J Prosthet Dent1984;51:54S.

12. Rugh JD, Graham G, Smith J, Ohrbach R. Effect of canineguidance versus molar occlusal splint guidance on noctur-nal bruxism and craniomandibular symptomology. JCraniomandib Disord Facial Oral Pain 1989;3:203-210.

13. Drago GJ, Rugh JD, Barghi N. Nightguard vertical thick-ness effects on nocturnal bruxism. J Dent Res1979;58:317.

14. Mejias JE, Metha NR. Subjective and objective evaluationof bruxing patients undergoing short-term splint therapy. JOral Rehabil 1982;9:279-289.

15. Lucia VO: Modern Gnathological Concepts-Updated.Chicago: Quintessence, 1983:439.

16. Neff PA. Anterior déprogrammer and its construction of itto determine initiating position. Presented before theAmerican Academy of Crown and Bridge Prosthodontics,Chicago, Feb 1981.

17. Dumas AL, Neff PA, Moaddab M, Perez L, Maxfield N,Salas A. A combined tomographic and cephalometricanalysis of the TMJ. J Craniomand Pract 1983;l:23--46.

18. MacDonald J, Hannam A. Relationship between jaw-clos-ing muscle activity during tooth clenching: Part 1. JProsthet Dent 1984;52:718-729.

19. Olceson JP. Management of TemporomandibularDisorders and Occlusion. St Louis: Mosby, 1989:349-355.

20. Nakamura T, Inoue T, Ishigaki S, Maryamura T. Theeffect of vertical dimension change on mandibular move-ments and muscle activity. Int j Prosthodont1988;l:297-301.

21. Okeson JP. Long-term treatment of disc interference disor-ders oí the temporomandibular joint with anterior reposi-tioning occlusal splints. J Prosthet Dent 1988;1611-615.

22. Guichet N. Clinical management of occlusally related oro-faciai pain and TMJ dysfunction. J Craniomand Pract1983;l:60-72.

23. Burch J. Selection of occlusal patterns in periodontai thera-py. Dent Clin North Am 1986Í24 :354 .

24. Neff PA. Occlusal therapy reshaping and/or restoring. ThePresident's Conference on the Examination, Diagnosis andmanagement of Temporomandibular Disorders. Chicago:American Dental Association, 1982:147-154.

25. Wruble M, Lumley M, McGIynn F. Sleep related bruxismand sleep variables: A critical review. J CraniomandibDisord Facial Oral Pain 1981^3:152-158.

26. Bush FM. Occlusal etiology of myofacial pain dysfunctionsyndrome. The President's Conference on theExamination, Diagnosis and Management ofTemporomandibular Disorders. Chicago: American DentalAssociation 1982: 95-102.

27. Neff PA. TMJ, Occlusion and Function. Washington, DC:Georgetown University School of Dentistry, 1987:49-50.

28. Williams WN, Lapointe L, Mahan PE, Cornell C. Theinfluence on TMJ and central incisor impairment on biteforce discrimination. J Graniomand Pract 1983;1:120-124.

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Resumen

Caracterización de 86 pacientes con bruxismo y estudioa largo pla2o de su manejo con dispositivos oclusales yotras modalidades terapéuticas

Luego de examinar a 353 pacientes, se determinó que 86respondieron afirmativamente a las preguntas que fueronhechas para detectar bruxismo. El perfil de los pacientes quebruxaban reveló que el 100% tenían interferencias en las excur-siones de trabajo, el 78% tenían interferencias en las excur-siones de balanza, y el 95.4% tenían un contacto prematuro enintercuspidación máxima. La que ja principal de la mayoría delos pacientes afectados por bruxismo estaba relacionada aldolor, y el 89.6% de los pacientes sufrían de un desorden cra-neomandibular. Los pacientes fueron tratados inicialmente conun desprogramador anterior, y luego fueron tratados con otrosdispositivos oclusales teniendo en cuenta ios signos y síntomasque se presentaran. El tratamiento definitivo fue determinadopor la relación maxilo-mandibular del paciente.

Zusammenfassung

Kennzeichnung von 86 zähneknirschenden Patientenund langfristigen Untersuchungen über derenBehandlung mit okklusalen Behelfen und anderenFormen von Threrapie

Von 353 überprüften Patienten, 86 gaben positive Antworten zuFragen, die für die Identifizierung von Zähneknirschern beab-sichtigt waren. Das zähneknirschende Patienten Profil zeigte,dass 100% praktische, abschweifenden Hinderungen hatten;78% hatten ausbalancierende, abschweifende Hinderungen,und 95.4% hatten einen vorzeitigen Kontakt zu einer maximalenInterkuspation. Die meisten der zähneknirschenden Patientenhatten eine Hauptbeschwerde, die mit Schmerz verbunden war;89.6% dieser Patienten hatten Kraniomandtbulare Störungen.Zuerst wurden die Patienten mit einem vorderen Umsteuerer(Déprogrammer) behandelt und später wurden sie mit anderenokklusalen Behelfen behandelt, je nach Anzeigen undSymptomen. Die endgültige Behandlung wurde durch das maxil-lomandibulare Verhältnis des Patienten entschieden.

60 Volume 7. Number 1. 1993